Directional control mechanism for antennas



June 21, 1955 E. L. BARRETT 2,711,527

DIRECTIONAL CONTROL MECHANISM FOR ANTENNAS Filed June '7, 1951 5 Sheets-Sheet l Imyzzm-rcv olweurd. L man re??- (Mum, Egx w MM -w 1-ronznE.

June 21, 1955 I E. BARRETT 2,711,527

DIRECTIONAL CONTROL MECHANISM FOR ANTENNAS Filed June 7, 1951 S Sheets-Sheet 2 1? I60 we I22.

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DIRECTIONAL CONTROL MECHANISM FOR ANTENNAS Filed June 7 1951. 3 Sheets-Sheet 3 \NE (WTF I we aclwavd L3. Yqrcrett" Uill'tfi li DIRECTIONAL CONTROL MECHANISM FOR ANTENNAS Edward L. Barrett, La Grange, Ill., assignor to Donald B. Alexander, Edgar R. Bourke, Henry T. Chamberlain, John F. Maunion, Ernest W. Schneider, Walter A. Wade, and Charles S. Vrtis, not individually, but as trustees of The Arthur J. Schmitt Foundation, a charitable trust Application June 7, 1951, Serial No. 230,266

8 Claims. (Cl. 340-226) The present invention relates to a directional control system for signal receiving antennas whereby the antenna mast may be selectively rotated to bring the antenna to a predetermined position of orientation conducive toward the reception of maximum signal strength from any selected transmitting station.

The present invention has been designed for use and illustrated herein in connection with television receiving antenna but it will be understood that the principles of the invention are applicable to use in the control of the position of other types of antenna structures, whether the same be employed for transmitting or receiving signals, and whether the signals be of relatively high or low frequency.

Because of the relatively high frequencies employed in connection with the transmission of television signals, the signals are directional and are possessed of a limited range. In order to increase the possibility of signal reception such antennas are ordinarily mounted as high as practicable above the earths surface, and in order to attain maximum signal strength from the different transmitting stations, the receiving antennas are frequently mounted for rotation about a vertical axis so that they may be readily oriented in the direction of the particular transmitting station whose signal is to be received.

It is among the principal objects of the present invention to provide a remote control means for rotating an antenna on its support, together with indicating means for indicating the directional position of the antenna at the remote control location or station. For convenience, in carrying out the above mentioned object, the remote control station will ordinarily be situated in the vicinity of the television receiver in order that the person or persons in attendance at the receiver may control the rotation of the antenna and at all times be apprised of the directional position of the antenna under control.

A more specific object of the invention is to provide a remote control system for regulating the directional position of an antenna which is, in the main, of an electrical nature and which includes a driving motor operatively geared to the antenna supporting mast, a direction indicator located at the control station, and a telemetering sysem operatively connecting the motor and indicator whereby the indicator is caused to follow the directional movements of the antenna so that the position of the former will at times render an indication of the position of the latter.

Another object of the invention is to provide a system of this character including a movable control member which may be set to a predetermined directional position and which, when so set, will effect energization of the antenna driving motor and maintain such energization of the motor until such time as the indicator, in following the movements of the rotatable antenna, moves into a position of register or coincidence with the control member.

In carrying out this last mentioned object, the invention contemplates the provision of a stepping magnet for the indicator which is so designed that upon initial enertates Patent Cfiice gization thereof the stepping impulse will be stored for subsequent use and released only when deenergization of the magnet takes place. A circuit maker and breaker is arranged in the magnet circuit and, additionally, a pair of normally closed contacts which remain open when the indicator and control member are in coincidence are disposed in the circuit in series with the magnet. Thus, if the antenna structure comes to rest when the contacts of the circuit maker and breaker are open, no further impulse is received by the stepping magnet. If, on the other hand, the antenna structure overruns its position before coming to rest so that the contacts of the circuit maker and breaker become closed when the antenna structure comes to rest, the open contacts in the magnet circuit existing by virtue of coincidence between the indicator and control knob, prevent a current impulse from reaching the magnet. Thus, the indicator can at no time overrun the control knob by virtue of a stored impulse in the circuit. By the same token, when the antenna structure comes to rest with the contacts of the circuit maker and breaker closed, manual setting of the control member to a new position out of coincidence with the indicator will merely serve to initiate an impulse in the stepping magnet, and this impulse will be stored until such time as movement of the antenna structure brings the latter into coincidence with the indicator.

Another object of the invention is to provide a followup system of the character briefly outlined above in which the antenna rotating motor is of the unidirectional type so that the follow-up movements of the motor, and consequenly of the antenna, in seeking a position commensurate with the adjusted position of the control member, will always be in the same direction regardless of whether large or small increments of position change are involved.

A further object of the invention is to provide a followup system of this sort in which any tendency for a hunting action between the antenna driving motor and the control member are eliminated.

Another object is to provide a directional control system 7 for antennas including a telemetering circuit between the movable member or antenna and the indicating member so that the latter will at all times indicate the position of the former and in which movement of the indicator is effected intermittently under the control of av stepping magnet which, in turn, receives impulses under the control of a circuit maker and breaker actuated by the antenna driving motor. A similar and related object is to provide a telemetering system of this character in which the impulses received by the stepping magnet are initiated upon closing of the telemetering circuit by the circuit maker and breaker and are subsequently released for actual stepping of the indicator when the circuit is opened. By such an arrangement limited overrunning of the antenna will not cause overrunning of the indicator to an extent sufiicient to effect an out-of-phase condition between the indicator and antenna during the next succeeding cycle of antenna adjustment.

A further object of the invention is to provide a directional control system for antenna masts in which the control mechanism at the control station is portable and, toward this end, extremely compact.

Another object is to provide such a system in which the driving and control mechanism at the antenna location is likewise extremely compact and is entirely enclosed and shielded against the ingress of moisture and dirt.

Still another object is to provide a device of this nature which may be readily marketable as an attachment for existing antenna installations.

Other objects and advantages of the invention, not at this time enumerated, will become more readily apparent as the nature of the invention is better understood.

in the accompanying three sheets of drawings forming a part of this specification, one embodiment of the invention has been shown.

In these drawings:

Figure 1 is a perspective view, somewhat schematic in its illustration, of an erected antenna system showing the improved control mechanism of the present invention applied thereto.

Fig. 2 is a side elevational view of the mast supporting structure in Fig. 1. In this view, certain parts have been broken away to more clearly reveal the nature of the control instrumentalities associated with the mast supporting structure.

Fig. 3 is a sectional view taken substantially along the line 33 of Fig. 2.

Fig. 4 is a sectional view taken substantially along the line 44 of Fig. 1.

Fig. 5 is a sectional view taken substantially along the line 55 of Fig. 4.

Fig. 6 is a sectional view taken substantially along the line 66 of Fig. 4.

Fig. 7 is a circuit diagram of the directional antenna control system showing the control knob thereof set for a predetermined adjustment of the directional position of the antenna and prior to initial movement of the latter.

Fig. 8 is a diagrammatic view similar to Fig. 7 showing the antenna and follow-up indicator in the course of their respective movements toward the predetermined angular position, and

Fig. 9 is a diagrammatic view similar to Figs. 7 and 8 showing the relative positions of the various mechanical and electrical parts employed after adjustment of the antenna to the predetermined angular position has been attained.

' While the invention is susceptible of various modifications and alternative constructions, there is shown in the drawings and will herein be described in detail the preferred embodiment, but it is to be understood that it is not thereby intended to limit the invention to the form disclosed, but it is intended to cover all modifications and alternative constructions falling within the spirit and scope of the invention as expressed in the appended claims.

Briefiy, the present invention contemplates the provision of an antenna mast supporting structure for maintaining in upright coaxial relation, fixed and rotatable mast sections and embodying means for gripping the mast sections which is capable of accommodating a relatively wide range of mast sizes. The control mechanism for actuating the rotatable mast section includes one set of instrumentalities located at the outlying antenna location,

and another set of instrumentalities located at the control station which may be in the vicinity of the television receiver. Among the control instrumentalities located at the outlying station are a driving motor which is operatively geared to the rotatable mast section for driving the same in one direction. The control instrumentalities at the control station include a fixed reference indicator and a rotatable control knob which may be manually adjusted to any desired position with respect to the fixed reference indicator. The control instrumentalities at the control station also-include a movable follow-up direction indicator which is adapted at all times to indicate the true directional position of the rotatable antenna mast. A circuit maker and breaker at the outlying station and operable under the control of the antenna driving motor is adapted to control the stepping movements of the direction indicator at the control location.

Two electric circuits are involved, one for controlling the energization of the driving motor and the other for controlling the energization of the stepping magnet. The circuit arrangement is such that when the control knob and direction indicator at the control station are in coincidence, the circuit through the electric driving motor and they circuit through the stepping magnet are both open. When the control knob is moved out of coincidence with the direction indicator, as for example, when Antenna Rotator, now Patent No. 2,668,920.

it is set to a predetermined position with respect to the fixed direction indicator, to which position it is desired that the antenna shall be rotated, the circuit through the driving motor is closed and the driving motor commences its operation of driving the rotatable antenna mast in one direction toward its ultimate destination. As soon as the driving motor has commenced its rotation, the circuit maker and breaker which now exists in a potentially closed circuit including the stepping magnet for the direction indicator, commences a series of periodic opening and closing movements. These movements serve to periodically energize the stepping magnet which in turn causes a periodic stepping or indexing of the direction indicator which then operates to followup" the previously adjusted control knob. Such stepping operations t'ake place until such time as the movable direction indicator moves into coincidence with the previously adjusted control knob and at this time the circuit through the driving motor as well as the circuit through the stepping magnet and circuit maker and breaker is opened thus rendering the entire set of control instrumentalities inoperative until such time as the control knob is again moved to a new position out of coincidence with the direction indicator.

Referring now to Figs. 1 and 2 of the drawings, the antenna installation includes the usual assembly of antenna elements designated in their entirety at 10 and which are suitably mounted upon a rotatable antenna mast section 12'. A fixed mast section 14 is disposed in coaxial alinement with the rotatable mast section 10, and the two sections are coupled together for rotation of the section 12 with respect to the section 14 by means of a control assembly including a housing 16 in which is disposed all of the control elements and instrumentalities at the outlying station.

The housing 16 is provided with a coaxially disposed, upwardly projecting post 18 which is' adapted to be inserted in the lower end of the rotatable mast section 12. In order to accommodate masts of various internal diameters, the post 18 is provided with a split conical bushing 20 therearound having an axial bore therein for reception of the post. It will be apparent that masts of relatively small internal diameters will engage the bushing 20 adjacent the upper region thereof, while masts of larger internal diameters will move further downwardly on the bushing.

The rotatable mast section 12 is mounted in coaxial relationship on the housing 16 by means of a supporting structure including an expansible and contractible clamping band 21 adapted to engage the mast section 12 at a region spaced upwardly above the housing 16 and a similar contractible band 22 adapted to engage the housing 16. A series of struts or supports 24 serves to connect the two bands 21 and 22 and maintain the rotatable mast structure or section 12 upright.

The housing 16 is formed in two sections including an upper section 26 and a lower section 28, the two sections being suitably secured together as by means of attachment screws 30. Means are provided whereby a rotary connection is obtained between the housing 16 and the fixed mast section 14. This means forms no part of the present invention, and for a full disclosure thereof reference may be had to my copending application, Serial No. 243,108, filed August 22, 1951, for an It is deemed sufiicient to state, for purposes of illustration that this connecting means includes a lower well or extension 32 formed on the lower casing section 28 and in which there is disposed a slip ring construction by means of which the rotatable and non-rotatable ends of the antenna lead-in wire tape or strap 34 may be electrically joined. together as well as through which the circuit. wires. employed in connection with the present control system may pass. A sealing gasket. 35 serves to seal the well 32 and clamping mechanism 35 against ingress of moisture or other foreign material. The slip ring construction forms no part of the present invention, and reference may be had to another copending application, Serial No. 230,267, filed June 7, 1951, for a Lead-In System for Rotatable Antennas for a full disclosure of this device.

Referring now to Fig. 2, the upper end of the nonrotatable mast section 14 is adapted to be received within a clamping mechanism including axially extending clamping arms 36 and sectional clamping bands 38. One of these clamping arms 36 serves to support thereon a terminal block 40 by means of which the circuit wires leading from the control station are connected to the antenna rotating assembly. The nature of the clamping assembly 35 may be determined by reference to my copending application, Serial No. 230,268, filed June 7, 1951, for an Antenna Mast Clamp, now Patent No. 2,692,745.

The upper ends of the clamping arms 36 project through the lower section 28 of the casing 16 and carry at their upper ends a stationary cage or framework 41 Within which there is supported the driving motor M for the rotatable mast section 12. Thus when the mast section 12 is fixedly secured to the upper housing section 26, rotation of the mast section 12 is obtained by rotating the entire housing 16 under the driving influence of the motor M.

The cage 41 is provided with a top wall 42 to which there is secured an inverted U-shaped bracket 44. The motor M is provided with a motor shaft 46 on which there is mounted a gear 48 (Figs. 2 and 3) which meshes with a larger gear 50 mounted on a shaft 52 journaled between the top wall 42 of the cage and the bracket 44. A small gear 54, which may be integrally formed with the gear 50, meshes with a larger gear 56 carried on a shaft 58 likewise journaled between the top wall 42 of the cage 41 and the bracket 44. A small gear 60, which may be integrally formed with the gear 56, meshes with a gear 62 mounted on a shaft 64 rotatably journaled between the top wall 42 of the cage 41 and the upper portion of a second inverted U-shaped bracket 66 suitably secured to the cage 41. A gear 68 is secured to the shaft 64 and is in constant mesh with a ring gear 70 which is centrally disposed within the upper casing section 42 and is secured in position by means of a series of radially spaced anchoring bolts 72. The ring gear 70 is recessed centrally to provide a socket 71 therein for reception of a thrust bearing 73 rotatively mounted on a post 75 carried on the bracket 44. The bearing 73 absorbs substantially all of the downward vertical thrust of the antenna installation, and relieves the resilient sealing gasket 35 provided on the lower portion of the well 32. From the above description of parts, it will be seen upon energization of the motor M and consequent rotation of the motor shaft 46 a direct drive will exist through the train of gears including the gears 48, 50, 54, 60, 62, 68 and 70 to the housing 16 on which the rotatable mast section 12 is mounted. Since the motor M is of the unidirectional type, any change in the directional position of the antenna will, of course, occur by rotation of the mast section 12 in a clockwise direction as viewed in Figs. 7, 8 and 9.

As will be more fully explained in connection with the wiring diagrams of Figs. 7, 8 and 9, the electrical connections for the motor include lead in wires collectively designated at 73 in Fig. 2 which extend from the terminal block 40 and pass through the slip ring construction 32 and are connected to the binding posts (not shown) of the motor M. The wires 73 are connected to respective wires 74 leading to the outlying antenna location from the control station.

Referring now 'to Fig. 3, the motor M has associated therewith an impulse transmitter mechanism designated in its entirety at 76 and including a contact assembly 79 and a rotary transmitter wheel 80 mounted on the shaft 64. The contact assembly 78 includes a pair of normally open contacts C1 and an operating finger 82 therefor, the end of which projects into the path of movement of a series of peripheral teeth 86 provided on the transmitter wheel 88. It will be seen that upon energization of the motor M and consequent rotation of the shaft 64 and transmitter wheel 80, the normally open contacts C1 will be periodically closed in order to send electrical impulses to the control station for purposes that will be made presently. The contacts C1 are also connected to the wires 73 which in turn are connected through the binding posts to the wires 74, respectively.

Referring now to Figs. 1, 4, 5 and 6, the mechanism at the control station, which may be located in the vicinity of the television receiver, is in the form of a small, unitary, contact control box or cabinet designated in its entirety at and including an outer casing 102 having side walls 104 and 106, a front or panel wall 108, and a domelike top wall 110. The front wall 108 is provided with a circulr opening 112 therein in which there is nested a cup-shaped dial unit 114 which may be calibrated with a series of radially spaced indicia marks 116, the space between adjacent indicia marks representing 6 of angular turning movement of the antenna 10. The cup-shaped dial unit 114 is provided with a central opening 118 therein in which there is secured a bushing 120. A nut 122 serves to secure the bushing in position within the opening 118. A sleeve 124 projects completely through the bushing 120 and the forward end of the sleeve is adapted to receive thereon a control knob 126 which is secured in position by means of a set screw 128. A shaft 130 extends through the sleeve 124 and the forward end thereof frictionally receives thereon an indicator or pointer 132 which is dis posed within a recess 134 formed in the front face of the knob 126 and which is adapted to be covered by means of a transparent cover 136, the rim portion of which is seated within the recess 134. The control knob 126 is provided with a pointer 138 designed for cooperation with the various indicia marks 116 provided on the face of the dial member 114.

Supported solely by the sleeve 124 is a bracket 140 having a laterally extending portion 142 and a downwardly extending portion 144 to which latter portion there is secured a solenoid assembly S.

According to the present invention, the indicator 132 is adapted to render an indication of the position of the antenna 10 whenever the antenna is at rest in a predetermined position. The control knob 126 is provided for the purpose of selecting a new antenna position, and when the pointer 138 thereof is swung to a position representing the desired antenna position, mechanism is set into motion for energizing the motor M and causing the antenna 10 to rotate toward the desired new position.

. As soon as such' rotation of the antenna commences,

the previously described transmitter 76, at the outlying location, is set into operation and impulses are forwarded to the solenoid S, and by means of this solenoid the indicator 132 is caused tofollow the positions of the antenna as the same moves toward its predetermined, selected new location, at which time the indicator 132 moves into register with the pointer 138, and at this time current for energizing the motor M is interrupted so that the antenna comes to rest.

In order to effect closing of the motor circuit, when the control knob 126 is moved to a new location representing a desired angular position of the antenna 10, and in order to effect follow-up movement of the indicator 132 as briefly outlined above, the inner end of the shaft 130 has mounted thereon a disk (Figs. 4 and 5) having a series of ratchet teeth 1S2 thereon. A holding pawl 154 cooperates with the teeth 152 in preventing reverse movement thereof. The disk 150 is adapted for rotational stepping or indexing movements in a counterclockwise direction as indicated by the arrow in Fig. 5.

In order to step or index the disk the solenoid S is provided with a movable core 159 which is spring pressed as at 161 to an extended position wherein it bears against a resilient limit stop 163. The core 259 carries an angle piece 165 to which there is secured a pawl 167 which cooperates with the teeth 152 provided on the disk 15%). It will be seen, therefore, that upon energization of the solenoid S, the core 159 will be retracted against the action of the spring 161 thus causing the pawl 167 to move over one of the teeth 152 on the disk 150 and assume a retracted position so that upon de-energization of the solenoid S the spring 161 will move the core 159 to its advanced position, thus carrying with it the pawl 167 and advancing the disk 56 throughot-it one increment of motion representing 6 of rotation of the indicator 132.

The rear end of the sleeve 124 carries a second disk 156 thereon having a series of detent teeth 156 formed on the periphery thereof. The teeth 158 cooperate with a retaining pawl 166 which permits rotation of the disk 156 in either direction but res-trains the same against such movement and serves to locate the disk 156 in any one of the sixty positions of angularit'y of which the disk 156 is capable of assuming.

Secured to for rotation therewith but spaced and insulated from the disk 356, is a contact arm 162 carrying a movable contact element 164 designed for cooperation with a fixed contact element 166 which is secured to and rotatable with the disk 156. The contact elements 164 and 166 cooperate to make up the pair of normally closed contacts designated in their entirety at C2. An electrical takeoff arm 168 bears as at 170 against the contact arm 162 and is secured to an insulating block 172 mounted on the bracket 146. Reference to Fig. 4 will reveal the fact that the contact 166 is electrically connected to the metal bracket 140 through the metal path leading through the disk 156, shaft 13 sleeve 124 to the bracket 146. Thus, when the normally insulated contact arm 162 is moved in such a direction as to close the pair of contacts C2, the take-off arm 168 becomes electrically connected or grounded to the bracket 140.

The free end of the contact arm 162 is provided with a laterally projecting finger 176 which projects through an opening 178 provided in the disk 150. The free 7 end of the finger 176 is designed for cooperation with a cam protuberance or button 189 formed of insulated material and carried on the disk 156 adjacent the periphery thereof. The contacts C2 are adapted to remain closed during all relative positions of the two disks 150 and 156 except the one relative position between these two disks which exists when the cam protuberance 180 is in engagement with the finger 176. Thus, as one or the other of the two disks rotates relative to its counterpart disk, a position of coincidence between the finger 176 and cam protuberance 180 will occur when a similar position of coincidence occurs between the indicator 132 and the control knob pointer 138. At such a time the normally closed contacts C2 will become opened.

A base member 200 extends across the open bottom end of the cabinet or casing 192 and is provided with a series of supporting feet 262 thereon. The base member 200 is provided with an upwardly extending portion 204 which constitutes a rear wall for the casing 102. The upstanding portion 204 of the base member 2% serves to support thereon a transformer T (see also Figs. 7, 8,

and 9), having a primary winding 266 and a secondary winding 208. The base member 200 is provided with a terminal binding post assembly 209 by means of which the circuit wires 74 leading from the control cabinet 102 will be secured in position and operatively connected to the various electrical instrumentalities associated therewith in the manner illustrated in Figs. 7, 8

and 9.

In Fig. 7, the antenna is shown as occupying a directional position which may generally be referred to as southwest, and the control knob 126 is shown as having been moved to a position which may generally be referred to as northwest and which indicates that it is the desire of the operator to swing the antenna 10 to this northwest position. As soon as the control knob 126 assumes its new position and is moved away from its original position, the insulated cam protuberance or button 130 moves out of register with the finger 176 as shown in Fig. 4 and the contacts C2 become closed, thus electrically connecting the frame or bracket 140 to one terminal of the transformer secondary winding A circuit then exists from the secondary winding 208 of the transformer T through leads a, b, winding of the motor M, leads 0, d, take-off arm 168, contacts C2, and lead e back to the secondary winding 298. Closure of the contacts C2 thus establishes a circuit through the motor M to energize the same and upon rotation of the motor shaft 46 in the direction indicated by the arrow in Fig. 7 the train of gearing previously described and including the gears 48, 50, 54, 56, 60, 62, 68 and serves to rotate the housing 16 of Fig. 2, and consequently the rotatable, mast section 12 and antenna 19 in a clockwise direction, as viewed in Fig. 7. Rotation of the antenna structurecontinues until such time as thc insulated protuberance or button 130, in its follow-up action, again engages the finger 176 thus opening the contacts C2 and discontinuing the motor circuit.

Immediately upon energization of the motor M and consequent rotation of its shaft 46, the impulse transmitter assembly 76 is set into operation. The gear ratio existing from the motor shaft 46, through the train of gearing leading up to the transmitter wheel 80, is so designed according to engineering exigencies that the transmitting wheel will make one complete revolution while the antenna 10, and consequently the indicator 132, moves throughout an angle of 48. In other words, inasmuch as there are eight teeth 86 on the wheel 80, successive impulses created by the transmitter by virtue of the closing of the contacts C1 will represent 6 increments of motion of the antenna and indicator. The impulse circuit leading through the contacts C1 extends from the secondary winding 208 of the transformer T through leads a, 1, contacts C1, lead g, the winding of the solenoiid S, leads h, d, take-off arm 168, contacts C2 (closed when the finger 176 and protuberance are out of register) and lead e back to the secondary winding 208. As each successive impulse is created by closure of the contacts C1, the solenoid S receives an impulse thereby advancing the pawl 167, which after 6 of rotational movement of the antenna, is released to advance the disk 150. The impulses are repetitive until such time as the finger 176 and button or protuberance 180 come into register, at which time the contacts C2 become open, thus opening the impulse circuit just described as well as opening the motor circuit.

The arrangement of the solenoid S whereby impulses received thereby upon closure of the contacts C1 are stored for subsequent release upon opening of the contacts C1, will preclude the possibility of the indicator 132 and the antenna 10 getting out-of-phase with each other due to overrunning of the motor M after a prolonged period of rotational sweep of the antenna, possibly augmented by a high wind. In such an event, even though the transmitter wheel 80 may overrun its normal position so as to cause closure of the contacts C1, the fact that the contacts C2 are open as soon as the indicator 132 and pointer 138 come into register will prevent an impulse from being received by the solenoid S. Even though the contacts C1 may remain closed after a particular angular setting of the antenna 10 has been efiected, and even though these contacts will remain closed when the control knob 126 is again moved to a new setting, the impulse applied to the solenoid S through both contacts C1 and C2 will merely be the normal impulse that would ordinarily be applied when the antenna arrived at its overrun position. In other words, any overrunning of the antenna throughout a few degrees of rotation will not be reflected by the indicator at the end of a particular cycle of operations but this reflection will immediately'take place at the beginning of the next cycle of operations so that the antenna and indicator will at all times be in phase with each other during stepping operations.

To state the above in still another way, overrunning of the antenna to a slight degree will have no eifect upon the indicator 132 during a particular cycle of operations. However, during the next cycle, such overrunning of the antenna will instantly be accounted for by a corresponding movement of the indicator and thereafter the indicator and antenna will move in unison.

In Fig. 8, the antenna 10 and transmitting wheel 80 are shown in a position wherein the contacts C1 are closed. In this view the solenoid S'is energized and its core or armature 159 is retracted. The pawl 167 is also retracted and the spring 161 is compressed. Preparatory to opening of either the contacts C1 or C2, the antenna 10 has moved to substantially its west position and stepping operations are in progress. The indicator 132 is shown as assuming its west position and the contacts C2 are closed inasmuch as the indicator 132 is out of register with the pointer 138. V

In Fig. 9, the indicator 132 has moved into register with the pointer 138 and both these elements as Well as the antenna 10 have assumed the northwest setting to which the control knob 126 has been adjusted. The contacts C2 are therefore open and the circuit through the motor is discontinued. Since there has been no overrunning of the antenna, the contacts C1 are also open but even if there had been overrunning of the antenna and closing or the contacts C1, the fact that the contacts C2 are open would preclude the possibility of an impulse of current being directed to the solenoid S.

I claim as my invention:

1. In a control device for a rotatable directional antenna, a motor adapted to be operatively connected thereto for rotating the same, a normally closed circuit for said motor, a movable indicator for indicating the directional position of the antenna, a settable control member movable into and out of register with the indicator, a stepping magnet for indexing the indicator throughout predetermined increments of motion, said magnet being operable upon energization thereof to become preset and operable uponde-energization to initiate the indexing operation of the indicator, a circuit for the magnet, an impulse emitter operable under the control of said motor for intermittently interrupting the magnet circuit, and means operable when the control member and indicator are in register for opening both of said circuits.

2. In a control device for a rotatable, directional antenna, a motor adapted to be operatively connected to the antenna in driving relationship, control means for operating said motor from a remote location, indicating means at said remote location for rendering a visual indication of the directional position of the antenna, said control means comprising an electric circuit for the motor including a source of current supply and a movable, settable control member, said indicating means including a movable indicator, said indicator and control member being relatively movable into and out of register with each other, a stepping magnet operable upon application of successive impulses thereto to index said indicator through predetermined increments of motion, an electric circuit for said stepping magnet, an impulse emitter operable under the control of said motor for successively energizing said stepping magnet, a pair of normally closed contacts common to said circuits and operable when closed to energize the magnet circuit and potentially close the magnet circuit for subsequent energization by said iii) trol member are in register for opening said contacts, said impulse emitter being eifective when said control member is moved out of register with said indicator to effect repeated energization of said stepping magnet a number of times sufiicient to advance the indicator into register with said control member.

3. In a control device for a rotatable, directional antenna, a motor adapted to be operatively connected to the antenna for rotating the same, a normally closed circuit for said motor, a movable indicator at a remote location for indicating the directional position of the antenna, a settable control member movable into and out of register withthe indicator, a stepping magnet for indexing the indicator throughout predetermined increments of motion, a circuit for said magnet, an impulse emitter operable under the control of said motor for successively closing and opening the magnet circuit, a pair of normally closed contacts common to said motor and magnet circuits, and means operable when said control member and indicator are in register to open said pair of contacts.

4. In a control device for a rotatable, directional antenna, a motor operatively connected to the antenna for driving the same from one position of adjustment to another selected position of adjustment, a normally closed circuit for the motor, a rotatable settable position selector at a remote location, a rotatable indicator, said position selector and indicator being relatively movable into and out of register with each other, a stepping magnet for indexing the position indicator throughout predetermined increments of motion, a circuit for the magnet, a pair of emitter contacts disposed in said magnet circuit, means operable upon energization of said motor for intermittently opening and closing said emitter contacts, and means operable when said position selector and indicator are in register for opening both of said circuits to render said emitter inelfective.

5. In a control device for a rotatable, directional antenna, a unidirectional motor adapted to be operatively connected to the antenna for driving the same in one direction from one position of adjustment to another selected position of adjustment, a normally closed circuit for the motor, control mechanism for operating said motor from a remote location, said control mechanism comprising a rotatable settable position selector at said remote location, a rotatable indicator, said position selector and indicator being relatively movable into and out of register with each other, a solenoid for indexing the position indicator, said solenoid being operable upon initial energization thereof to become preset and being operable upon de-energization thereof to effect indexing of the position indicator, a circuit for the solenoid, an impulse emitter in said circuit and operable under the control of said motor for successively energizing said solenoid, and means operable when said position selector and indicator are in register for opening both of said circuits to render said emitter ineffective.

6. In a control device for a directional antenna, a motor adapted to be operatively connected thereto for rotating the same, a normally closed circuit for the motor, means at a remote location for controlling the movements of the motor and consequently of the antenna and for indicating the position of the latter, said means comprising an indicator disk mounted for rotation about an axis, direction indicating means on said disk establishing the position thereof relative to a fixed point, a manually operable settable selector disk spaced from said indicator disk and mounted for rotation about the axis of the latter, a direction pointer on said selector disk to facilitate setting of the latter relative to a fixed point, said pointer and direction indicating means being movable into and out of register with each other upon relative rotational movement between said disks, a stepping magnet for indexing the indicator disk throughout predetermined increments of rotation, a circuit for the magnet, an impulse emitter emitter, and means operable when said indicator and con- [5 operable under the control of said motor for intermittently interrupting said magnet circuit, a pair of normally closed contacts mounted on and rotatable with one of said disks, said contacts being common to both the magnet and the motor circuits, and means carried on the other disk and engageable with said pair of contacts when said indicating means and pointer are in register for opening said contacts to de-energize said motor and to render said emitter ineffective.

7. In a control device for a rotatable, directional antenna, a motor adapted to be operatively connected thereto for rotating the same, an electric circuit for the motor, means at a remote location for controlling the movements of the motor and consequently of the antenna and for indicating the position of the latter, said means comprising an indicator disk mounted for rotation about an axis, direction indicating means on said disk establishing the position thereof relative to a fixed point, a manually operable settable selector disk spaced from said indicator disk and mounted for rotation about the axis of the latter, a direction pointer on said selector disk to facilitate setting of the latter relative to a fixed point, said pointer and direction indicating means being movable into and out of register with each other upon relative rotational movement between said disks, a stepping magnet for indexing the indicator disk throughout predetermined increments of rotation, a circuit for said magnet, an impulse emitter operable under the control of said motor for intermittently interrupting the magnet circuit, a source of current for energizing said circuits, a pair of normally closed contacts mounted on one of said disks and rotatable in unison therewith, one contact of said pair being electrically connected in both of said circuits, the other contact of said pair being electrically connected to said source or" current supply, and cam means carried by the other disk and engageable with said pair of contacts when said indicating means and pointer are in register for opening said contacts to de-energize said motor and to render said emitter ineffective.

8. In a control device for a rotatable, directional antenna, a motor adapted to be operatively connected thereto for rotating the same, an electric circuit for the motor,

means at a remote location for controlling the movements of the motor and consequently of the antenna and for indicating the position of the latter, said means comprising an indicator disk mounted for rotation about an axis, direction indicating means on said disk establishing the position thereof relative to a fixed point, a manually operable settable selectordisk spaced from said indicator disk and mounted for rotation about the axis of the latter, a direction pointer on said selector disk to facilitate setting of the latter relative to a fixed point, said pointer and direction indicating means being'movable into and out of register with each other upon relative rotational movement between said disks, a stepping magnet for indexing the indicator disk throughout predetermined increments of rotation, a circuit for said magnet, an impulse emitter operable under the control of said motor for intermittentl'y interrupting the magnet circuit, an electrical contact mounted on one of said disks and fixed relative thereto, said contact being electrically disposed in both the motor and magnet circuits, a relatively movable contact also carried by said latter disk and movable into and out of contact with said relatively fixed contact, means normally maintaining said contacts in engagement, and means carried by said other disk and engageable with said movable contact when said indicating means and pointer are in registe'rfor moving said relatively movable contact out of engagement with said fixed contact, a source of energizing current common to said circuits, and means electrically connecting said relatively movable contact to said source.

References Cited in the file of this patent UNITED STATES PATENTS 714,862 Buck Dec. 2, 1902 993,814 Barnum May 30, 1911 1,018,765 Janette Feb. 27, 1912 1,416,340 Dippel May 16, 1922 1,788,793 Hall Jan. 13, 1931 2,559,339 Blease et a1 July 3, 1951 

